Optical communication systems are widely used today for data communication. In addition to the transmitters and receivers in coherent optical communication systems, there may also be bandwidth limited optical components included in the transmission channel between the transmitter and receiver that cause inter-symbol interference impairments in the transmitted signal. The optical fiber used as the transmission channel to support high data rate transmissions may induce phase noise related impairments. Providing adequate compensation for these impairments is important for designing a robust receiver that is capable of recovering of the transmitted signals.
Digital Multi-band (DMB) transmission is a multiplexing technique that can provide a flexibility of transmission data rates for different signals being transmitted. DMB allow use of different Forward Error Correction (FEC) coding and modulation rates for different tones, provide rate variability through sub-carrier bandwidth variation and provide variable transmission bandwidth granularity by increasing or decreasing a number of tones being transmitted.
Because of the variability of transmission characteristics associated with DMB transmission, there may be benefit to emphasizing different types of compensation for different impairments that can dominate different bands of a multi-band signal.